Does Clipping Work in Blender 2.9?
From  your screen shot, you enabled &quot;render region&quot; rather than clipping region. Not sure what's the correct key bind in Mac OS, but in windows, it's Ctrl + B (Which might be eq to Cmd + B in common translation).
Please look at the menu again, it said Alt + B to create clipping region, as the following picture show. Red dashed line is for render region, and it's separated from clipping region.

Remember, It is &quot;clipped&quot;, not hidden. It should only be working in Solid or Wired Frame view mode. On the other hand, render region only works during rendering in Cycles.